1. Field of the Invention
The present invention relates to a device for the formation and transfer of groups of articles. In particular, the present invention relates to a device for the formation of a group of articles on a conveyor and the transfer of the group from one processing operation to another. More particularly, the present invention relates to a device for transferring groups of articles at right angles to the initial feed direction. More particularly yet, the present invention relates to a device that uses pneumatic controls to group the bottles and transfer them to a filling operation.
2. Description of Prior Art
Conveyors are commonly used in manufacturing and food processing operations to move articles or goods from one operation to another. For many types of operations it is advantageous to have the articles grouped for batch processing. Such typical batch-processing operations include applying labels to bottles or cans or other types of containers, packing bottles, cans or boxes into crates, or filling containers with liquid or semi-liquid material. A number of devices or systems are known that group articles for batch processing. Many of the systems known in the prior art use a system of endless chains that run alongside one side or both sides of the conveyor transporting the articles to be processed. Typically, these chains run at a slower speed than the conveyor and have lugs, pins, or rods arranged on them at predetermined distances that are moved into the path of the conveyor and inserted between the articles on the conveyor as a means of breaking a continuous flow articles into groups of articles. The device disclosed by Dardaine (U.S. Pat. No. 3,190,434;1962) is illustrative of many of the devices that use an endless chain running parallel to the conveyor. Stop members or pins are mounted on the endless chain at intervals that correspond to the distance of six bottles. The endless chain runs at a slower speed than the belt. As the chain is driven around a sprocket, a first stop member is moved into the path of the bottles on the belt and inserted between two bottles. This slows the bottles on the upstream side of the stop member while allowing the bottles downstream of the stop member to proceed at the speed of the belt. As the chain travels parallel to the belt, the first stop member will pull away from the path of the belt downstream from its initial insertion point as a second stop member is moving into the path, slowing down the travel speed of the next batch of bottles and thus, creating a space between the first group and the second group of articles.
The devices of the above mentioned type have several disadvantages: they are cumbersome and require a certain amount of space to each side of the conveyor belt; they are material-intensive and thus, expensive; they are also power-intensive because they run continuously; and they are loud. Furthermore, these devices do not change the configuration of the number of articles abreast, i.e., they do not convert a single or double file feed of articles to multiple articles abreast, but merely create a distance between one group of rows of articles and a following group. Ganz (U.S. Pat. No. 3,680,678; 1972) does teach the formation of a group of several articles abreast, converted from a single-file feed of articles. The method and apparatus that Ganz uses to form multiple articles abreast, however, requires a substantial amount of linear space because single-feed articles must first run through a restricted section of the belt to force them into a nesting formation, and then through a section providing the full width required by the cluster for proper spacing. Furthermore, none of these devices manipulates the articles so as to move them onto a second conveyor or processing line that is situated at right angles. Space requirements often do not allow for a long processing run in one direction; utilization of space is sometimes more efficient if articles can be manipulated to move to the left or right of the feed conveyor.
A number of devices that group articles on a conveyor belt use overhead grippers to transfer the grouped articles to a second conveyor or another station. Mokler (U.S. Pat. No. 5,579,893; 1996) teaches the use of two conveyors at right angles to each other to receive articles from a single file feed conveyor and to pass them on at right angles in rows of several articles abreast. The transfer mechanism used to move the articles from the first conveyor to the second one is an overhead gripper that uses suction force to lift the articles and a release of the force to drop the articles onto the second conveyor. The configuration of the suction gripper determines how many rows are transferred in a single operation. A disadvantage of this method of transferring articles from one conveyor to another is that the suction gripper is a complex device that is not well-suited for gripping tall, narrow objects such as bottles.
Draghetti (U.S. Pat. No. 5,133,446) teaches the use of a pusher that moves a single file group of articles into a receiving bay on a table at right angles to the direction of the single file feed line. A conveyor belt having slats mounted on it runs in an endless loop above the table, the slats on the lower part of the loop forming a receiving bay adjacent to the single-file feed line. The bay moves with the belt in a direction parallel to the single-file feed line and drags the articles in the receiving bay along a table surface and onto a second feed line that is situated at right angles to the direction of the single file feed line. The Draghetti device is designed to group articles in a predetermined configuration of rows and columns for an operation that treats the presented group as a single unit, such as a wrapping operation; the device does not present a continuous feed of rows of articles in an operation that processes the individual articles, such as a filling or labeling operation. It is also designed to transfer objects that are not very tall and that have regular dimensions, such as straight-sided cylinders or substantially rectangular containers. The Draghetti device is not suited to transfer tall narrow objects, such as beer bottles, because the receiving bay slats would have to be correspondingly long and that would make it difficult to drag the bottles along the surface, as the slats are mounted on a belt and not on a rigid structure that would provide the rigidity and force required to move such articles.
Conveyors and batch-processing are often used in operations in which bottles or cans or jars are filled with a liquid or semiliquid material. In such operations spillage is always a possibility. For this reason, having a system that is safe to use in a wet environment is advantageous. All of the grouping systems described above rely on electrical means to control and drive the devices. Such systems may represent a hazard in filling operations where spillage can occur.
Therefore, what is needed is an inexpensive yet rugged device for grouping articles What is further needed is such a device that will group articles in rows and continuously feed the rows at a 90.degree. angle to the next processing operation. What is yet further needed is a device that is safe to operate in a wet environment and easy to maintain. What is still further needed is a device that does not significantly increase the space requirements beyond the requirements for the conveyor system.